WANG Lu, FU Bin, YANG Xiao xiang

 

(School of Machine Engineering and Automation, Fuzhou University, Fuzhou 350116, China)

 

 

Abstract: Aiming at discovering the change rule of Mullins effect on carbon reinforced natural rubber, 3 kinds of natural rubber test pieces filled with different mass fractions for 15.1%, 24.7% and 38.2% were loaded in simple tension from their virgin states to find out what changes can be brought out by different stretching rate, recovery time and the amount of carbon black. Simple variable method was used, and all the experiments were under process control. Corresponding stretching scheme was applied respectively in the test researching for stretching rate, recovery time and the amount of carbon black to study these factors′ influences to Mullins effect. The results indicate that Mullins effect is intensified when the rubber is filled with larger amount of carbon black. In addition, when extension ratio is less than 1.5, the longer the recovery time is given between circles, the weaker the Mullins effect becomes and even disappears. Moreover, the results show that if the extension ratio is less than 1.5, Mullins effect gets weaker as the stretching rate increases which can be seen clearly after some certain circles. However, as the deformation goes larger, Mullins effect becomes stronger and finally be a characteristic of the stretch curves.

 

Key words: carbon reinforced; simple tension; Mullins effect; stretching rate; recovery time